The Hunt for a Second Earth

As basic biology demonstrates, water is essential in order for life to exist. Therefore in the search for another habitable planet, that planet must be able to harbor liquid water. This may seem like a simple thing to ask for but it’s a little more complicated than that. The need for liquid water means that a planet must orbit at just the right distance away from its star (“Home Hunting in the Universe”). The planet must be at a distance that the heat from the star is not hot enough for all the water to evaporate but at the same time it can’t be too cold that all the water freezes (“Home Hunting in the Universe”).

Apart from Earth, Mars is thought to be the only planet in the solar system in which life is most likely to exist. The NASA Mars rovers Spirit and Opportunity have both gathered evidence that liquid water had once existed on the planet Mars (Larson, Extraterrestrials). There is also evidence that water may exist on the planet even today, either beneath its surface or in its polar ice caps (Larson, Extraterrestrials). Although the chances of there being life forms as sophisticated as humans on Mars is slim, it would still be remarkable to witness some form of life on another planet. This would certainly give aspirations to mankind to search for more life in the universe.

To assist further in the search for a second-Earth, on March 6, 2009, NASA launched an unmanned spacecraft named Kepler into space (Tanenbaum). Its main task is to use its high-tech telescope to find a habitable planet in another solar system (Tanenbaum). It will monitor about 100,000 stars for the next three to six years and report its findings back to Earth (Tanenbaum). There are high hopes for Kepler, partly due to the discovery of planet Gliese 581c about twenty light years away that is quite simply the most Earth-like planet yet detected orbiting another star (Larson, Another Earth). This super-Earth, which has a mass five times that of Earth, is considerably closer to Gliese 581 (its star) than Earth is to the Sun (Larson, Another Earth). However, the star is also smaller than the Sun therefore this planet lies in the “habitable zone” and can nurture water at a temperature between 0 and 40 degrees Celsius (Larson, Another Earth). This temperature is perfect for supporting life; unfortunately this paradise is currently out of reach for current space travel capabilities.

Works Cited:

Larson, Chris. "Another Earth?" Today’s Science. Facts On File News Services, May 2007. Web. 1 Dec. 2009. .

Larson, Chris. "Extraterrestrials: The Search Gets Serious." Today’s Science On File: n. pag. Today’s Science. Facts On File News Services, 30 June 2005. Web. 1 Dec. 2009. .

"Home Hunting in the Universe." Today’s Science. Facts On File News Services, July 2009. Web. 1 Dec. 2009. .

Tanenbaum, Jessica. "The Kepler Mission: NASA's Newest Planet Finder." Today’s Science. Facts On File News Services, Apr. 2009. Web. 1 Dec. 2009. .

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